Hyundeok Park airglow923

Get Public IP

DNS

Google

dig o-o.myaddr.l.google.com txt @ns1.google.com +short
# OR
nslookup -type=txt o-o.myaddr.l.google.com ns1.google.com

Below are the steps to get an ARM64 version of Ubuntu running in the QEMU emulator on Windows 10.

Install QEMU

Install for Windows from https://qemu.weilnetz.de/w64/ (I used qemu-w64-setup-20181211.exe)

Put C:\Program Files\qemu on your PATH, and run the below to check it's working (which will list out the CPUs the AArch64 emulator can emulate):

qemu-system-aarch64 -M virt -cpu help

C++ : Polymorphic inheritance without vtable

Inheritance and Virtual Table are often used to create interface in C++ polymorphic class
What if ... there were another way to do this ?
easier, cleaner, faster and more reliable
This article explains how to use CRTP, [std::variant](https://en.cppreference.com/w/cpp/utility/variant and std::visit to increase code performance.

Table of content

Introduction

How to use?

Copy content of vsix-bookmarklet, create a bookmark in your browser.
Navigate to the web page of the VS Code extension you want to install.
Click the bookmark you just created, then click the download button.
After download finished, rename the file extension to *.vsix.
In VS Code, select Install from VSIX... in the extension context menu.

m3u8 Downloading

Open Chrome Developer tools and click the Network tab.
Navigate to the page with the video and get it to start playing.
Filter the list of files to "m3u8".
Find master.m3u8 or index.m3u8 and click on it.
Save the file to disk and look inside it.
If the file contains a single m3u8 master url, copy that one instead.
Run the program m3u8x.
Paste the same m3u8 url in both textboxes (URL and Quality URL) and click "Headers" and set the referral url and user-agent from the request as found in Chrome.

security and hardening options for systemd service units

A common and reliable pattern in service unit files is thus:

NoNewPrivileges=yes
PrivateTmp=yes
PrivateDevices=yes
DevicePolicy=closed
ProtectSystem=strict

References:

Overview

Priority values

From man page: man apt_preferences

	#!/usr/bin/env bash

	set -Eeuo pipefail
	trap cleanup SIGINT SIGTERM ERR EXIT

	script_dir=$(cd "$(dirname "${BASH_SOURCE[0]}")" &>/dev/null && pwd -P)

	usage() {
	cat <<EOF
	Usage: $(basename "${BASH_SOURCE[0]}") [-h] [-v] [-f] -p param_value arg1 [arg2...]

	[*]
	charset = utf-8
	end_of_line = lf
	indent_size = 2
	indent_style = space
	insert_final_newline = false
	max_line_length = 100
	tab_width = 2
	ij_continuation_indent_size = 4
	ij_formatter_off_tag = @formatter:off


	// --------------------------------------------------------------------------------------
	// Atomic singly-linked intrusive list using 128-bits Compare And Swap (AKA: DCAS).
	// Keeps a version counter with the list head to prevent the A-B-A problem.
	//
	// Based on the implementation found in moodycamel.com:
	// http://moodycamel.com/blog/2014/solving-the-aba-problem-for-lock-free-free-lists
	//
	// My implementation uses raw GCC/Clang atomics intrinsics. While in theory
	// std::atomic of a struct of exactly 16 bytes and properly aligned could